Definition of Interactive Whiteboard
An interactive whiteboard or IWB, is a large interactive display that connects to a computer and projector. A projector projects the computer's desktop onto the board's surface, where users control the computer using a pen, finger or other device.

http://upload.wikimedia.org/wikipedia/commons/a/a2/Interactive_whiteboard_at_CeBIT_2007.jpg
http://upload.wikimedia.org/wikipedia/commons/a/a2/Interactive_whiteboard_at_CeBIT_2007.jpg